Example Program - Mitsubishi FX1N Series User Manual

5. Example Program

An analog output is converted from a digital value (D8114) using the DA conversion characteristic
specified by special auxiliary relay M8114 at each END instruction.
5.1 Allocated Device
Table 5.1: Allocation of Device
Device
Switch of output mode
M8114 OFF:
ON:
D8114 Digital value (When power supply is turned ON, D8114 will initials to "0".)
Note:
This D/A conversion is done regardless of the RUN/STOP status of the PLC. Any time power
is supplied to the PLC when the 1DA is attached, the analog value in D8114 will be output.
The analog output value will continue to be output when the PLC status is changed from RUN
to STOP!
5.2 Basic Example Program
Note:
Drive M8114 which specifies the digital to analog conversion characteristic with M8000 ("a"
type contact of the RUN monitor) or M8001 ("b" type contact of the RUN monitor).
Do not change the ON/OFF state while the digital to analog conversion is operating.
The Digital to analog conversion is not executed correctly when M8114 is turned ON and OFF
during the conversion process.
5.2.1 Voltage Output Mode
The following program example sets the voltage output mode, and a digital value in D0 is converted to
analog.
M8001
M8000
FNC 12
MOV
*1 If a digital value is not stored in D0, D8114 can be used directly for other instructions.
5.2.2 Current Output Mode
The following program example sets the current output mode, and a digital value in D2 is converted to
analog.
M8000
FNC 12
MOV
*1 If a digital value is not stored in D2, D8114 can be used directly for other instructions.
5.3 Example Application Program
As the 1DA does not have Offset and Gain capabilities, if values are required outside the standard
specification range, additional program commands are required to either multiply or divide the conversion
values. For an example application program, please see FX programming manual II.
Note:
• Accuracy and resolution of the digital to analog conversion are different from the
specification because of the additional program commands.
• The original range of the analog output is not changed.
Voltage output mode (0 ~ 10V)
Current output mode (4 ~ 20mA)
M8114
*1
D0 D8114
M8114
*1
D2 D8114
Description
Set in voltage output mode (0 ~ 10V).
*1
D0 is converted digital value to analog output.
Set in current output mode (4 ~ 20mA).
*1
D2 is converted digital value to analog output.